where is the cybertron mode

One thing i never understood in Transformers is why do they look the same after they scan a Earth vehicle
like in Cybertron before they came to Earth
they looked exactly the same in robot mode
i didnt see them in vehicle mode
but wouldnt they look totally different
like in Cybertron before they came to Earth
they looked exactly the same in robot mode
i didnt see them in vehicle mode
but wouldnt they look totally different